The present invention relates to a braking pressure control device, in particular for automotive vehicles equipped with an anti-lock control system (ABS) and/or a traction slip control system (TSC).
The braking pressure control device of this type tends to form a residual pressure in the wheel brake when operating in the low-temperature range during the slip-controlled pressure reduction phase due to the viscosity of the brake fluid. Because of the unsatisfactory pressure relief of the wheel brake, in particular when disc brakes are used, the wheel acceleration ability may be impaired undesirably after opening of the outlet valve, since the pressure accumulated in front of the opened outlet valve may react on the piston in the wheel brake cylinder under the action of the auxiliary pressure pump during slip control. Also, the long control spring required due to the relatively high pressure to be reduced causes a related delayed response behavior during braking pressure control.
Therefore, it is an object of the present invention to improve upon a braking pressure control device of the type referred to in order to overcome the disadvantages described and to realize in a cost-saving fashion a slip-controlled pressure reduction phase with reduced formation of residual pressure in the wheel brake.